Commit 253a2817 authored by Chris Wilson's avatar Chris Wilson
Browse files

drm/i915: Remove superfluous worker wakeups when RPS is already boosted 

We only need to wake up the RPS worker once when initially enabling the
client boost, it remains in effect then until the last client no longer
requires the boost.

References: https://bugs.freedesktop.org/show_bug.cgi?id=102250


References: 7b92c1bd ("drm/i915: Avoid keeping waitboost active for signaling threads")
Signed-off-by: default avatarChris Wilson <chris@chris-wilson.co.uk>
Cc: Michał Winiarski <michal.winiarski@intel.com>
Reviewed-by: default avatarMichał Winiarski <michal.winiarski@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20180206143137.15509-1-chris@chris-wilson.co.uk
parent 020580ff

drivers/gpu/drm/i915/i915_gem_request.c

+4 −2
Original line number Diff line number Diff line
@@ -443,12 +443,14 @@ static void i915_gem_request_retire(struct drm_i915_gem_request *request) 
	engine->last_retired_context = request->ctx;



	spin_lock_irq(&request->lock);

	if (request->waitboost)

		atomic_dec(&request->i915->gt_pm.rps.num_waiters);

	if (!test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &request->fence.flags))

		dma_fence_signal_locked(&request->fence);

	if (test_bit(DMA_FENCE_FLAG_ENABLE_SIGNAL_BIT, &request->fence.flags))

		intel_engine_cancel_signaling(request);

	if (request->waitboost) {

		GEM_BUG_ON(!atomic_read(&request->i915->gt_pm.rps.num_waiters));

		atomic_dec(&request->i915->gt_pm.rps.num_waiters);

	}

	spin_unlock_irq(&request->lock);



	i915_priotree_fini(request->i915, &request->priotree);

drivers/gpu/drm/i915/intel_pm.c

+6 −3
Original line number Diff line number Diff line
@@ -6374,12 +6374,15 @@ void gen6_rps_boost(struct drm_i915_gem_request *rq, 
	if (!rps->enabled)

		return;



	if (test_bit(DMA_FENCE_FLAG_SIGNALED_BIT, &rq->fence.flags))

		return;



	/* Serializes with i915_gem_request_retire() */

	boost = false;

	spin_lock_irqsave(&rq->lock, flags);

	if (!rq->waitboost && !i915_gem_request_completed(rq)) {

		atomic_inc(&rps->num_waiters);

	if (!rq->waitboost && !dma_fence_is_signaled_locked(&rq->fence)) {

		boost = !atomic_fetch_inc(&rps->num_waiters);

		rq->waitboost = true;

		boost = true;

	}

	spin_unlock_irqrestore(&rq->lock, flags);

	if (!boost)

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